CPU, Application, and Thread Fundamentals
📌 The CPU (Central Control Unit) is essential as it processes all applications; without it, applications cannot run.
⚙️ The thread is the basic unit that the CPU can process; an application cannot exist or perform tasks without at least one thread (usually the main thread or primary thread).
🔄 When an application runs, its thread must be assigned to the CPU for processing.

Role of the Thread Scheduler
⏱️ The Thread Scheduler, part of the operating system, acts as the intermediary, assigning available threads to the CPU(s).
⚖️ The scheduler bases assignments on various factors, including priority (mission-critical tasks) and ensuring fairness by preventing thread starvation.
⏳ Scheduling often involves time slicing, where each thread gets a specific time period to run on the CPU before being swapped out.

Multithreading Concepts
🧑‍💻 A program with multiple threads within a single application is referred to as a multithreading program or application.
🧠 To the Thread Scheduler, all threads across all running applications are treated equally; it only sees a collection of threads (e.g., five threads total in the OS), regardless of which application they belong to.
💽 In systems with multiple CPU cores, the scheduler assigns one thread per available core simultaneously.

Key Points & Insights
➡️ Developers cannot directly influence the Thread Scheduler, only potentially assign priorities to their own threads.
➡️ The fundamental unit the CPU processes is the thread, not the application itself.
➡️ Multithreading is defined by having multiple threads *within* one application, which the OS scheduler manages uniformly with other system threads.

📸 Video summarized with SummaryTube.com on Nov 14, 2025, 01:01 UTC